The present invention relates to improvements in oral irrigation and, more particularly, to a novel method and apparatus for employing water under pressure to cleanse and massage the user's oral cavity.
Oral irrigators are well known in the prior art. One such apparatus, as described in U.S. Pat. No. 3,227,158 to Mattingly, issues a pulsed water jet through a nozzle under the driving action of an electrically-operated pump. The pulse act to massage the user's gums and loosen food particles lodged between the teeth and between the teeth and gums. In order to provide an effective gum massage, the repetition rate of the pulses is selected to permit the user's gums to rebound from their depressed state between successive pulses. Typically this repetition rate is on the order of 1000 to 1600 pulses per minute.
Subsequent developments recognized certain disadvantages in the Mattingly approach and set out to provide improvements. For example, U.S. Pat. No. 3,542,017 to Adams points out the shock hazard involved in using an electrically-operated pump and the cumbersome nature of the overall apparatus. To this end, Adams employs a fluidic oscillator to supply the pulsating water jet, the oscillator requiring no moving parts, whereby the requirement for an electrically-operated pump is eliminated. Adams makes no mention of the pulse repetition rate in his patent; however, in view of Mattingly's analysis, for effective massage the pulsed jet repetition rate must be on the order of 1000 to 1600 pulses per minute in order to permit the gum the rebound between pulses. There is a major practical disadvantage associated with the Adams irrigator. Specifically, the oscillating power stream in the fluidic oscillator must be oscillated between one outlet passage which feeds the outlet tube and a second outlet passage which serves as a vent. The venting wastes half of the applied water, a factor which is an anathema to present day stress on water conservation.
Still another prior art approach is illustrated in U.S. Pat. No. Re. 26,589 to Murov et al. The oral irrigator disclosed in that patent also avoids the use of electricity by using the pressure of the water to reciprocate the irrigator outlet tube. As a consequence, liquid is translated back and forth across the gums as the outlet tube reciprocates. The reciprocating drive mechanism in this device renders the device somewhat bulky and subject to failure because of the wear and tear between moving parts. Moreover, there is a practical limit to the frequency at which the outlet tube can be reciprocated.
It is therefore an object of the present invention to provide an oral irrigator which is operated solely by the applied tap water and has minimal pressure loss downstream of the oscillator, and utilizes all of the applied water in the irrigating flow.
It is another object of the present invention to provide an oral irrigator which can operate at substantially higher frequencies than prior art devices without sacrificing any effectiveness in its gum massaging action.
It is also an object of the present invention to provide a method of oral irrigation wherein tap water serves as the sole power source, pressure loss downstream of the oscillatory member is minimized and water waste is eliminated.
It is still another object of the present invention to provide a method of oral irrigation wherein operating frequencies far in excess of those employed in the prior art can be used without sacrificing effective gum massaging.